Systems for anchoring a medical device in a body lumen

ABSTRACT

A system for securing a device in tissue, having a sheath having a plurality of side openings; a rotatable element disposed within the sheath; and a plurality of curved projections extending from the rotatable element, wherein rotation of the rotatable element within the sheath pushes distal ends of each of the curved projections outwardly through one of the plurality of openings and into the tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/955,869, filed Nov. 29, 2010, now U.S. Pat. No. 8,202,281, which is acontinuation of U.S. application Ser. No. 11/552,593, filed Oct. 25,2006, now U.S. Pat. No. 7,842,049, which is a divisional application ofU.S. patent application Ser. No. 10/335,147, filed Dec. 31, 2002,entitled “Systems for Anchoring a Medical Device in a Body Lumen”, nowU.S. Pat. No. 7,160,309, the disclosures of which are incorporatedherein by this reference in their entireties.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates in general to systems for anchoringmedical devices in body lumens, or body cavities. In particular, thepresent invention relates to systems for anchoring catheters in bodylumens, which may include blood vessels.

2. The Relevant Technology

Various medical procedures require the anchoring of a medical devicewithin a body lumen. All of these systems need to be designed so thatthe device can be removed at the end of the procedure without causingunacceptable amounts tissue damage. For example, in the case of acatheter anchored in a blood vessel, the catheter must be easilyinserted through an opening in the side of the vessel yet also be easilyanchored when positioned at its desired location in the vessel.

A variety of systems have been designed to anchor a catheter passinginto a body lumen through an opening in the side of the body lumen. Mostcommonly, an inflatable balloon is mounted on the catheter. After thecatheter has been positioned at a desired location, the balloon isinflated. The balloon thereby pushes against the walls of the body lumenadjacent to the side opening when the catheter is pulled back, thusholding the catheter in position. Unfortunately, a problem with usingsuch an inflatable balloon is that it typically blocks fluid flowthrough the lumen, which may not be desirable. Also, in addition toinhibiting fluid circulation, the balloon may interfere with drugdelivery systems in the catheter.

What is instead desired is a simple system for securing a medical devicesuch as a catheter in a body lumen. Such a system would preferably notinterfere with fluid flow through the body lumen (such as blocking fluidflow with an inflatable balloon). In addition, such an anchoring systemwould preferably be easily removable at the end of the medicalprocedure.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a versatile system for securing a medicaldevice (such as a catheter) at preferred locations within a body lumen(such as a blood vessel) without blocking or substantially inhibitingfluid flow through the lumen.

In preferred embodiments, the present invention includes a sheath havinga plurality of side openings; a rotatable element disposed within thesheath; and a plurality of curved projections extending from therotatable element, wherein rotation of the rotatable element withrespect to the sheath pushes distal ends of each of the curvedprojections outwardly through one of the plurality of openings. Inpreferred methods of use, the plurality of curved projections areextended outwardly from the rotatable element and are then used to braceagainst the tissue surrounding a side hole opening into the vessel.Thus, when the device is deployed within the body lumen, and then pulledback (ie: proximally), the curved projections contact the tissuesurrounding the side opening into the vessel, thereby preventing thedevice from being removed. The deployed projections may also provideneedle receiving locations in the case of a suturing device, such as adevice for suturing an arteriotomy.

The present invention also includes an embodiment including a sheathhaving only one side opening with one curved projection extending fromthe rotatable element. Similar to the above design, rotation of therotatable element with respect to the sheath pushes the distal end ofthe curved projection outwardly through the side opening. In thisembodiment, the curved projection may be a wire having one end attachedto the rotatable element.

In optional preferred embodiments, the curved projection(s) may bebiased to spring radially outwardly as they pass through the sideopening(s) in the sheath. Alternatively, or in addition, the curvedprojection(s) may be formed from a shape memory material which assiststhem in springing radially outwards as they pass through the sideopening(s) in the sheath.

In various embodiments, the curved projection(s) may either be attachedto the rotatable element, or they may be integrally formed into therotatable element.

In various preferred embodiments, the curved projections are oppositeends of a deformable element such as a wire or ribbon. Most preferably,such deformable element passes through (or is fitted around) the centralrotatable element.

The present invention also provides a method of anchoring a device in abody lumen or cavity, including inserting the device into the body lumenor cavity, and rotating the rotatable element with respect to thesheath, thereby causing the distal ends of each of the curvedprojections to move outwardly through one of the one or more openingsand into the body lumen or cavity. In preferred embodiments of thepresent method, the body lumen may be any blood vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a first embodiment of the inventionprior to its deployment.

FIG. 1B is a perspective view of the first embodiment of the inventionafter it has been deployed.

FIG. 2A is a top plan view corresponding to FIG. 1A, showing the devicepassing through a side opening in a vessel lumen, with the distal end ofthe device positioned within the vessel lumen.

FIG. 2B is a top plan view corresponding to FIG. 1B, showing the devicepassing through a side opening in a vessel lumen, with the distal end ofthe device anchored in the vessel lumen.

FIG. 3A is a side view corresponding to FIG. 2A.

FIG. 3B is a side view corresponding to FIG. 2B.

FIG. 4 is a perspective view of a second embodiment of the invention.

FIG. 5A is a perspective view of a third embodiment of the inventionprior to its deployment.

FIG. 5B is a perspective view of the third embodiment of the inventionafter it has been deployed.

FIG. 6A is a perspective view of a fourth embodiment of the inventionhaving only one side opening in the sheath.

FIG. 6B is a sectional elevation view corresponding to FIG. 6A.

FIG. 7A is a perspective view of a fifth embodiment of the invention, inwhich the invention comprises a suturing device, after its arms havebeen deployed, but prior to suturing a tissue hole.

FIG. 7B is a perspective view corresponding to FIG. 7A, but after thetissue hole has been sutured.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1A to 3B illustrate a first embodiment of the invention whichdeploys two curved projections that can be used as an anchor againsttissue surrounding an opening into a vessel lumen. In this particularexample, the two curved projections are opposite ends of a single ribbonshaped element which passes through a central rotatable element of thedevice. The present invention is not so limited. Rather, otherembodiments are also contemplated.

For example, FIGS. 4A and 4B illustrate a second embodiment of theinvention which deploys four curved projections. This embodiment issimilar to the first embodiment, but instead uses two ribbon shapedelements which are spaced longitudinally apart from one another. FIGS.5A and 5B illustrate a third embodiment of the invention which deploysfour curved projections into the tissue. In this particular example, thecurved projections may either be attached to the central rotatableelement, or may be integrally formed with the central rotatable element.FIGS. 6A and 6B illustrate a fourth embodiment of the invention whichdeploys a single curved projection in the form of a wire attached at oneend to the central rotatable element. Lastly, FIGS. 7A and 7B illustratea fifth embodiment of the invention in which a suturing device includesneedles and suture in operative relationships with the anchoringelements or projections.

Each of the four embodiments of the invention (FIGS. 1A to 6B)illustrate the present invention as incorporated into a catheter system.Thus, for clarity, each of FIGS. 1A, 1B, and 4 to 6B illustrates only acut-out longitudinal section of a catheter system in which the presentinvention is incorporated. FIGS. 3A and 3B show a greater length of thecatheter. As can be appreciated, the catheter extends upwardly and/ordownwardly perpendicular from the page in FIGS. 2A and 2B.

Referring first to FIGS. 1A, 2A and 3A, a system 10 for securing acatheter system in a body lumen is provided. Sheath 12 has a pair ofside openings 14 disposed on opposite sides thereof. A central rotatableelement 20 is received within sheath 12. A pair of projections 22A and22B extend radially outwardly from rotatable element 20, as shown inFIGS. 1A, 2A and 3B. The sheath described herein may be a portion of acatheter body, an introducer sheath, or simply a hollow tubular bodythat is part of a device into which the present invention isincorporated. As will also be explained and illustrated, the presentinvention may be used in applications other than in a catheter body. Forexample, the present invention may be incorporated into a suturingdevice as shown in FIGS. 7A and 7B. It is to be understood, however,that the present invention may be incorporated into other devices aswell.

Returning to FIGS. 1A, 2A and 3A, rotation of rotatable element 20within sheath 12 in direction R (FIG. 2A) causes the distal ends of eachof projections 22A and 22B to be pushed out through openings 14. Thus,rotation of rotatable element 20 with respect to sheath 12 in directionR moves curved projections 22A and 22B from the pre-deployed position(FIGS. 1A, 2A and 3A) to the fully deployed position (FIGS. 1B, 2B and3B). As can be seen in FIG. 3B, such deployment causes curvedprojections 22A and 22B to extend beyond the edges E of side hole 11 inthe wall W of body lumen L. Thus, curved projections 22A and 22B can actas an anchoring system, such that they will push against the interiorsurface of wall W when the catheter system 10 is pulled proximally indirection P.

It is to be understood that all reference herein made to rotation of therotatable element (which is disposed within the sheath) both in thespecification and claims, refers to rotation of the rotatable elementwith respect to the sheath. Thus, “rotation of the rotatable element” inthe specification and claims, encompasses rotation of the rotatableelement with the sheath held stationary, rotation of the sheath with therotatable element held stationary, rotation of the sheath and rotatableelement in opposite directions, and rotation of the sheath and rotatableelement in the same direction, but at different speeds.

As can be appreciated, removal of the present anchoring system isaccomplished by simply rotating rotatable element 20 with respect tosheath 12 in a direction opposite to R, thereby retracting curvedprojections 22A and 22B into the sheath.

As shown in FIGS. 1A to 3B, curved projections 22A and 22B move throughside openings 14 which are disposed on opposite sides of sheath 12.Thus, in various embodiments, any number of side openings 14 may bedisposed equidistantly around the circumference of sheath 12.

Projections 22A and 22B may be curved. The projections preferably extendradially from the rotatable element in a plane that may be perpendicularor otherwise transverse to the longitudinal axis of the device or to therotatable element. Specifically, the projections 22A and 22B movethrough side openings 14 as the projections are deployed in a radialdirection with respect to the axis of the device. Such movement in theradial direction may preferably be confined to movement in thetransverse plane defined by the lengths of the projections.

In the preferred embodiment illustrated in FIGS. 1A to 3B, projections22A and 22B are simply opposite ends of a single deformable member 22which passes through a hole 21 in rotatable element 20. Deformablemember 22 (and its curved projections 22A and 22B) may be formed from aribbon shaped material (having a rectangular cross section, as shown).Alternatively, deformable member 22 (and its curved projections 22A and22B) may be formed from a wire (having a circular cross section). Infurther embodiments, deformable member 22 (and its curved projections22A and 22B) may be formed from a member having an I-beam cross section.

An advantage of curved projections 22A and 22B being ribbon shaped orI-beam shaped (or any other dimension in which they are thicker in thedirection along the length of sheath 12) is that they are more resistantto bending when the catheter is pulled in direction P, such that theprojections push against the tissue surrounding the interior of opening11 through tissue wall W (see FIG. 3B).

It is to be understood that although curved projections 22A and 22B maybe opposite ends of a single deformable member 22 (as shown), curvedprojections 22A and 22B may also be two separate elements which eitherare fastened to rotatable element 20 or are integrally formed from thesame block of material as rotatable element 20. Whether or not curvedprojections 22A and 22B are opposite ends of a single member, or areseparate elements, such curved projections are preferably formed from adeformable material. Suitable deformable materials may include (but arenot limited to) metals, including shape memory metals, polymers, or anycombinations thereof.

In optional preferred embodiments, curved projections 22A and 22B may beformed of a material which causes them to be biased such that their endsspring radially outwardly (i.e.: straighten out) as they pass throughside openings 14. An example of this effect can be seen in FIG. 2B wherethe curved radially extending ends of projections 22A and 22B are shownas being straighter than the center portion of deformable member 22 thatis inside sheath 12. This is advantageous in that it is the straightestportion of deformable member 22 protrudes radially away from the centerof the device, and reaching farther, thus maximizing the amount oftissue against which the projections are anchored.

Optionally, curved projections 22A and 22B may be formed of a shapememory material (such as Nitinol). As such, curved projections 22A and22B may thus be formed to spring radially outwardly (i.e.: straightenout) when they are exposed to a temperature change. For example, curvedprojections 22A and 22B could be exposed to a temperature change as theyexit windows 14 by being warmed by the fluid passing through the bodylumen.

FIG. 4 illustrates an embodiment of the invention having two pairs ofcurved projections. Specifically, a first pair comprising curvedprojections 22A and 22B, and a second pair comprising curved projections24A and 24B. Thus, in this embodiment side openings 14 are also disposedlongitudinally along the length of the sheath (as well as about thecircumference of the shaft). As illustrated, curved projections 22A and22B are opposite ends of a first deformable element 22 passing throughhole 21A while 24A and 24B are opposite ends of a second deformableelement 24 passing through hole 21B.

FIGS. 5A and 5B illustrate yet another embodiment of the invention inwhich four curved projections 22A, 22B, 22C and 22D each extend fromcentral rotatable element 20. In this embodiment, four curvedprojections are used. It is to be understood however that, in accordancewith the present invention, any plurality of curved projections can beused. These curved projections protrude through openings which may bedisposed equidistantly around the circumference of shaft 12. Forexample, curved projections 22A, 22B, 22C and 22D are shown as disposedat 90 degrees to one another.

FIGS. 6A and 6B illustrate yet another embodiment of the invention inwhich a single curved projection 22A is deployed through a single sideopening 14. In this embodiment, curved projection 22A is one end of awire (or other suitable deformable member) 22 which is wrapped around(and attached at one end to) central rotatable element 20. In thisembodiment, the length of wire 22 may optionally be as long, or longerthan, deformable member 22 as shown in the other embodiments. Thus, wire22 can be rotated such that its distal end (curved projection 22A) isdeployed much father through side opening 14 than is shown in theprevious embodiments. This would have the effect of causing wire 22, andits distal end (i.e. curved projection 22A) to extend farther around thecircumference of sheath 12, thus firmly anchoring the present device inposition. FIGS. 6A and 6B show wire 22 extending approximately half wayaround the circumference of the device. It is to be understood that thedistal end of wire 22 (i.e. curved projection 22A) may also-extend evenfurther around the circumference of the device. For example, the distalend of wire 22 may be extended fully around the device, or even further(so that it wraps around the circumference of the device several times).

In various embodiments, the present invention is substantially enclosedwithin the body of the catheter, thus saving space and permitting easyaccess into the interior of body lumen L.

In various preferred embodiments, the present system is dimensioned tobe around 5 to 10 mm in diameter, but may instead be dimensioned smallerso that it may fit into vessels less than 5 mm in diameter.

The various embodiments of the invention which are incorporated into acatheter system do not block fluid flow when anchoring a catheter in abody lumen. Thus, the present invention may conveniently be used inconjunction with systems either for drug or therapeutic energy delivery,or with diagnostic systems.

In an alternate embodiment, shown in FIGS. 7A and 7B, the device is asuturing device 30 that is anchored on the interior side of a vesselwall through an arteriotomy. The device 30 may include suture-carryingor holding features located on extendable projections 32 in order toretrieve sutures S1 and S2 when device 30 provides an arteriotomyclosure. In accordance with this embodiment, projections 32 are deployedradially outwardly in the same fashion that projections 22 were deployedin the previously described embodiments (eg: by rotating rotatableelement 20 within device 30).

The suture-carrying features may be recesses formed in projections 32.For example, the suture-carrying features may include cuffs 33 that maybe attached to the ends SI and S2 of a length of suture which runsthrough the center of device 30. Cuffs 33 can be held within recesses inprojections 32. The present suture-carrying features may include cuffs,but the present invention is not so limited. For example, the ends ofthe suture can alternatively be formed into other features that areconnectable to needles, such as loops. Suturing device 30 furthercomprises a pair of needles 34 that are initially disposed on anexterior of lumen L as shown in FIG. 7A. Thereafter, needles 34 areadvanced so that they pass through the wall of the vessel, such thateach needle 34 is received into a cuff 33. Thereafter, needles 34 areretracted, as shown in FIG. 7B, each pulling a cuff 33 with a length ofsuture (S1 or S2) attached thereto out of the proximal end of device 30.Thereafter, extendable projections 32 can be retracted radially inwardly(by rotating element 20 in an opposite direction) so that the distal endof device 30 may be removed from the hole in the side of the artery,leaving behind suture passing therethrough, which can be used to closethe hole. It is to be understood that although device 30 is illustratedas having two needles 34, cuffs 33 and sutures S1 and S2, otherembodiments having more needles, cuffs and sutures are also possible. Asillustrated in FIGS. 7A and 7B, the needles of such a device are wouldengage the cuffs and pull the suture through tissue.

What is claimed is:
 1. A system for anchoring a device, comprising: asheath having a plurality of side openings; a rotatable element disposedwithin the sheath; and at least two projections extending radially fromand attached to the rotatable element, wherein rotation of the rotatableelement with respect to the sheath advances the distal ends of theprojections radially outwardly through the openings, one of the twoprojections being distal the other of the two projections, wherein theat least two projections are formed from a shape memory material, andwherein the at least two projections spring radially outwardly as theypass outwardly through the side opening as the rotatable element isrotated with respect to the sheath when the at least two projections areexposed to a temperature change.
 2. The system of claim 1, wherein theat least two projections is directly connected to the rotatable element.3. The system of claim 1, wherein the at least two projections isintegrally formed with the rotatable element.
 4. The system of claim 1,wherein the shape memory material is Nitinol.
 5. The system of claim 1,wherein the at least two projections comprises four projections disposedat 90 degrees to one another around the rotatable element.
 6. The systemof claim 1, wherein the plurality of side openings are disposedlongitudinally along the length of the sheath.
 7. The system of claim 1,wherein the projections extend radially in a plane that is perpendicularto the longitudinal axis of the system.
 8. The system of claim 1,further comprising a suture-carrying feature on each of the ends of thedistal ends of the projections.
 9. A method of tissue closure,comprising: inserting a distal end of a device having a sheath with atleast a pair of side openings, a rotatable element within the sheath,and two pairs of projections, each projections having a distal end and asuture-carrying feature thereon, extending radially from the rotatableelement, the pairs of projections attached to the rotatable element, oneof the pair of projections being distal the other of the pair ofprojections, the suture-carrying feature attached to an end of a suture,wherein rotation of the rotatable element with respect to the sheathpushes each distal end of the projections radially outwardly through theeach openings into an artery; advancing a needle through a wall of theartery and into the suture-carrying feature; and withdrawing the needlethrough the wall of the artery to pull the end of the suture through thewall of the artery.
 10. The method of claim 9, wherein withdrawing theneedle through the wall of the artery to pull the end of the suturethrough the wall of the artery comprises withdrawing a pair of needlesthrough the wall of the artery, to pull a pair of suture ends throughthe wall of the artery.
 11. The method of claim 9, wherein thesuture-carrying feature is a cuff at an end of the suture.
 12. Themethod of claim 9, further comprising rotating the rotatable element toextend the pairs of projections through the pairs of side openings. 13.The method of claim 12, wherein the two pairs of projections extendthrough the two pairs of side openings, the side openings being disposedat 90 degrees to one another around the sheath.
 14. The method of claim13, wherein each of the projections curves outwardly through arespective opening of the two pairs of side openings.
 15. The method ofclaim 13, wherein one pair of projections extend radially through onepair of side openings in a first plane that is perpendicular to alongitudinal axis of the system.
 16. The method of claim 15, whereinanother pair of projections extend radially through another pair of sideopening in a second plane distal the first plane, the second plane beingparallel to the first plane.